We at the British Society for Ecological Medicine (BSEM) have been talking to the Pernicious Anaemia Society (PAS). Martyn Hooper and his colleagues there have achieved a remarkable amount, with 3,500 members after just two years, and a questionnaire that identifies several key symptoms of B12 deficiency about which none of us knew — the “strange tiredness” and “the gulps” for instance. We are looking forward to working with them, both to help sufferers and to prove that B12 deficiency is a real problem for many people. More of that on our website.

Here I want to talk about my own experiences with B12, which I’ve been using for more than 20 years — although we have learnt more all the time since then.

The first thing to say is that B12 is extremely safe. In all that time I have seen one instance of adverse effects, and that was back when we used cyanocobalamin — the original version if you like — and in a complicated case with other problems. Since we have used methylcobalamin and hydroxocobalamin the only adverse effect I have known is one male patient who called me from his car; he was on the way to casualty because just after the injection of B12 that I gave him his urine had turned pink! I was able to reassure him that it was simply overflow of the B12 he had received.